This invention relates to the automatic packing of articles (e.g., cans or bottles) in paperboard cartons. The invention is particularly suited for use with certain automatic packaging apparatus called "wraparound" packaging machines. Such wraparound machines package articles by folding, or "wrapping", a flat corrugated paperboard carton blank having various panels and flaps defined by score lines around a group of such articles (usually arranged in a rectangular or square pattern, e.g., 4 by 3) to be packaged. This is in contrast with automatic packing apparatus wherein the articles to be packed are automatically placed, individually or in groups, in partially or fully erected paperboard cartons, which cartons are then sealed.
The advantages of making automatic wraparound packing machinery fast and reliable, and at the same time relatively inexpensive, are apparent. However, prior to the present invention, high speed wraparound packing machinery was typically relatively more expensive and complicated.
Typical automatic wraparound packing machinery employs a conveyor belt to feed the cans or other articles from the filling and capping station toward that part of the apparatus adapted for wrapping the carton blank around the groups of articles to be packed. This conveyor belt typically is disposed at a 90.degree. angle to the direction of feed through the machine, in order to to provide an area, sometimes referred to as a "holding station", between the aforementioned feed conveyor belt and the rest of the machine in which the cans or other articles to be packed are assembled into groups for packing. A second conveyor belt for transporting the packed cartons away from the packing machinery is typically positioned below the level of the feed conveyor belt. Such packing machinery also typically feeds the flat, unfolded carton blanks horizontally onto a vertically movable platform, or "lowerator", which is automatically raised to the level of the aforementioned feed conveyor belt for receiving the articles to be packed, and lowered to the level of the aforementioned second conveyor belt for discharging the packed cartons and for transporting the packed cartons away from the packing machinery.
With the movable platform in its upper position at the level of the first conveyor, and with the carton blank in place on the platform, a group of cans or other articles is typically moved into place from the holding station onto the blank by a reciprocating mechanism, or "pusher".
With the articles in place on the blank, the platform is lowered to the level of the discharge conveyor belt, the carton blank being automatically partially "wrapped" or folded along its score lines around its contents as the platform is being lowered from the level of the feed conveyor belt to the level of the discharge conveyor belt. Thereafter the carton is moved automatically, typically by a piston-actuated ram, onto the discharge conveyor belt. The automatic folding operation is completed and the carton flaps are glued in place as the carton moves from the lowerator to the second conveyor belt. The platform is then raised to receive the next carton blank and group of articles to be packed.
Disadvantages of the aforementioned typical apparatus and method of wraparound packing should be apparent. For example, delay is incurred in the packing process while the moving platform is being raised and the carton blank moved into position on the platform. Further delay is incurred while the reciprocating pusher moves a group of articles onto the carton blank and withdraws. And because the feed conveyor belt is disposed horizontally at a 90.degree. angle to the direction of flow through the packing machine, the operation is less efficient and there is a greater danger that articles will be damaged than if the articles were permitted to flow in the same horizontal direction throughout the packing process.
My invention overcomes these and other disadvantages of prior automatic wraparound packing machines, and permits packing speeds of up to 22 cartons per minute, whereas the machinery described above typically operates at a maximum packing speed of around 15 cartons per minute.
Accordingly, an object of this invention is to provide a relatively fast, efficient, simple and economical method of packing articles, for example, cans, in paperboard cartons.
Another object of this invention is to provide means for avoiding packing delays found in certain automatic wraparound packing machinery, thereby improving packing speed.
Another object of this invention is to provide means for simplifying automatic wraparound packing machinery, making such machinery less expensive and easier to maintain, while at the same time permitting high speed operation of at least 22 cartons per minute.
Another object of my invention is to provide means for reducing the risk of damage to the articles to be packed by avoiding feeding the articles to the packing apparatus at a horizontal angle of 90.degree. to the direction of feed through the machine.